TDI has been developing fiber optic sensors and systems for medicine and industry since 1980; medical sensors completed (i.e., pressure, temperature) and under development (i.e., pH, pCO2, P02) have been licensed for use in disposable intravascular catheters. These disposable 'smart catheters' will be manufactured and marketed by a major U.S. catheter company beginning in 1985. The present Phase I program deals with development of a novel fiber optic glucose sensor for intravascular applications. A preliminary sensor design has been identified. The program will focus on development of an appropriated chemical substrate, chemical indicator, and enzyme system for specific and reversible detection of blood glucose. Subsequently, a prototype glucose sensor and supporting optoelectronic instrumentation will be fabricated and tested under laboratory conditions to demonstrate design feasibility. The market for intravascular 'smart catheters' is just now emerging. A 'smart catheter' containing the TDI fiber optic glucose sensor will provide for on-line, real-time measurements of intravascular glucose and at a cost comparable to that for one or two in vitro laboratory measurements.